Arteriovenous Malformations

What are arteriovenous malformations?

Arteriovenous malformations (AVMs) are groups of blood vessels in your body that form in the wrong way. In AVMs, arteries and veins are abnormally tangled.

AVMs can form anywhere in the body. They often occur as the body develops before birth or shortly after. Those that form in the brain or close to the spinal cord are called neurological AVMs. These are most likely to have long-term effects. They may reduce the amount of oxygen getting to the brain and spinal cord. AVMs can also sometimes put pressure on nearby tissues.

Most people with an AVM don’t know they have one. They may not have any symptoms or problems. Instead, AVMs are often found when healthcare providers treat some other unrelated health concern. Or one of the blood vessels in an AVM may rupture, revealing the problem. Sometimes AVMs are found only after death, during an autopsy.

What causes arteriovenous malformations?

No one knows why AVMs form. Some experts believe that the risk of developing AVMs could be genetic.

What are the symptoms of arteriovenous malformations?

Most people with AVMs will never have any problems. If symptoms don't appear by age 50, they likely will never will.

Women may have symptoms as a result of pregnancy. Being pregnant can put pressure on the blood vessels.

Symptoms of an AVM depends on where it is located. You may have:

Buzzing or rushing sound in the ears

Headache—although no specific type of headache has been identified

Backache

Seizures

Loss of sensation in part of the body

Muscle weakness

Changes in vision

Facial paralysis

Drooping eyelids

Problems speaking

Changes in the sense of smell

Problems with motion

Dizziness

Loss of consciousness

How are arteriovenous malformations diagnosed?

Healthcare providers will ask about a person’s past health and symptoms. They will also do a physical exam. They may talk with family and friends about a person’s symptoms if he or she is unconscious.

The final diagnosis is often made based on imaging tests. These tests can show areas of blood flow:

Cerebral angiogram

MRI scan and magnetic resonance angiography

CT scan and CT angiography

Vascular ultrasound

How are arteriovenous malformations treated?

A treatment plan is developed based on the size and location of the AVM. Treatments may include:

Medicine for symptoms

Plugging off the malformed blood vessels (embolization)

Surgery

Radiation therapy

Talk with your healthcare provider about the risks and benefits of your treatment options.

What are possible complications of arteriovenous malformations?

The main concern with AVMs is that they may cause uncontrolled bleeding (hemorrhage). A small percentage of AVMs bleed. But those that do can have severe effects. They may result in death.

Other complications of AVMs are:

Stroke

Numbness in part of the body

Problems with speech or movement

Spinal fluid buildup in the brain (hydrocephalus)

Lower quality of life

Can arteriovenous malformations be prevented?

AVMs happen before birth or shortly after. Their cause is unknown. So you can’t prevent them. The best approach is to respond quickly to symptoms.

When should I call my healthcare provider?

Some people find out about an AVM only when it bleeds. This causes stroke in some people. Go right away to the emergency room or call 911 if you have these symptoms:

Seizure

Numbness

Vomiting

Physical weakness

Key points about arteriovenous malformations

Arteriovenous malformations (AVMs) are groups of blood vessels in your body that form in the wrong way.

AVMs often develop before birth or shortly after. They may be genetic.

Most people with AVMs will never have any problems.

If a person does have symptoms, they depend on where the AVM is located. Symptoms may include headache, backache, seizures, or dizziness.

Imaging tests, such as an MRI, can often find an AVM.

Treatment options may include certain medicines or surgery.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

Know the reason for your visit and what you want to happen.

Before your visit, write down questions you want answered.

Bring someone with you to help you ask questions and remember what your provider tells you.

At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

Ask if your condition can be treated in other ways.

Know why a test or procedure is recommended and what the results could mean.

Know what to expect if you do not take the medicine or have the test or procedure.

If you have a follow-up appointment, write down the date, time, and purpose for that visit.